Guys,

What are the symptoms of the intake / plenum gasket needing replaced on the 318 magnum motors in these trucks? My 2001 has 135,000 miles, and it feels very under powered. Also, when I step on the gas, my vents stop blowing air - which makes me think there is a vacuum problem? I have had this truck for 5 years - and only have put 10,000 miles on it. It is basically my weekend hauler and trailer puller a couple times a year. What do you think? Is there a way to troubleshoot if it is the intake gasket?